The funding round is reportedly from Google parent company Alphabet. The Airbnb source would not comment on investors behind the round.

The $550 million goes toward $850 million the company filed to raise in July. The round values Airbnb at $30 billion, making it one of the biggest startups in recent years to remain private.

Airbnb’s fundraising round hasn’t closed and the company will have additional filings, the source said.

Google Capital and growth-equity firm Technology Crossover Ventures led the round, according to the Journal.

As part of the deal, employees who have been with Airbnb for longer than four years reportedly were able to sell common shares to investors, totaling $200 million. This has become an important way for companies to reward their employees without having to enter the public market.

Google Capital is a growth-equity arm of the company that has invested incompanies including SurveyMonkey, GlassDoor, Care.com and Duolingo.